Enhanced temperature coefficient of resistance in nanostructured Nd0.6Sr0.4MnO3 thin films

Abstract

Manganite thin films are promising candidates for studying strongly correlated electron systems. Understanding the growth and morphology-driven changes in the physical properties of manganite thin films is vital for their applications in oxitronics. This work reports the morphological, structural, and electrical transport properties of nanostructured Nd0.6Sr0.4MnO3 thin films fabricated using the pulsed laser deposition technique. Scanning electron microscopy imaging of the thin films revealed two prominent surface morphologies: a granular and a crossed-nano-rod-type morphology. From X-ray diffraction and atomic force microscopy analysis, we found that the observed nanostructures resulted from altered growth modes on the terraced substrate surface. Furthermore, investigations on the electrical-transport properties of thin films revealed that the films with crossed-nano-rod morphology showed a sharp resistive transition near the metal-to-insulator transition. Also, an enhanced temperature coefficient of resistance (TCR) of up to one order of magnitude was observed compared to the films with granular morphology. Such enhancement in TCR% by tuning the morphology makes these thin films promising candidates for developing oxide-based temperature sensors and detectors.